Look with love at a leg, possibly (4)
I believe the answer is:
ogle
'look' is the definition.
(I know that ogle is a type of look)
'love at a leg possibly' is the wordplay.
'love' becomes 'o' (love means zero in tennis).
'at' is a charade indicator (letters next to each other).
'possibly' indicates an anagram.
'leg' anagrammed gives 'gle'.
'o'+'gle'='OGLE'
'with' acts as a link.
(Other definitions for ogle that I've seen before include "Eye lecherously" , "Look at with amorous intentions" , "Perv" , "Lasciviously look" , "Amorous stare" .)